If there are any other entries for split() calls, all of them should be replaced with explode() one by one. You can find these calls by searching for 'split(' pattern in code, with grep (on Mac and LInux) or findstr (on Windows), for example:

$ grep " split(" -r path/to/magento/

# findstr /s /p /i /n /c:"split(" path\to\magento

Though, all warnings about deprecated split() function are non-critical and can be turned off simply by replacing error_reporting function in index.php: